1. Field of the Invention
This invention pertains to the field of polyurethane polymers. More particularly, this invention relates to the field of MDI based flexible polyether polyurethane foam.
2. Description of the Prior Art
Polyurethane polymers such as polyurethane elastomers and foams are broadly produced by reacting an aromatic polyisocyanate with a polyol such as a polyester polyol or a polyether polyol in the presence of a catalyst. One useful class of organic polyisocyanates employed to form polyurethanes are diisocyanates. In some instances, the diphenylmethane diisocyanates (MDI-type isocyanates) have been found to be somewhat lacking in utility. For example, it has been found that when one employs a diphenylmethane diisocyanate to prepare one shot water blown flexible foams using a polyether polyol that the resultant foam tends to split badly. These types of foams are desirable since they are highly resilient (HR). It has been found that this splitting problem may be efficiently and economically solved by the method of this invention. Therefore, an object of this invention to provide a flexible, high resilient water blown polyurethane foam which maintains excellent properties and processes without splitting.